| ⊦ mk(rs -- r, f) = mk(rs, f) -- r |
⊦ H0 = H1 ↔ (∀ r. (r ∈ H0 ↔ r ∈ H1) ∧ (r ∈ H0 → H0[r] = H1[r]))
⊦ ∀ r0. (r0 ∈ mk(rs -- r, f) ↔ r0 ∈ mk(rs, f) -- r) ∧ (r0 ∈ mk(rs -- r, f) → mk(rs -- r, f)[r0] = (mk(rs, f) -- r)[r0])
Used terms: mk(rs, f) -- r, mk(rs -- r, f)